Reversible pump-motor assembly for a dishwasher



Aug. 6, 1963 F. E. LA FLAME 3,099,992

REVERSIBLE PUMP-MOTOR ASSEMBLY FOR A DISHWASHER Filed Nov. 28, 1961 3 Sheets-Sheet l Fig. 48 E 36 7 I22 INVENTOR. B Frank E. LaF/ame l 6 I44 "6 Fig. 2

His A/fomey Aug. 6, 1963 F. E. LA FLAME 3,099,992

REVERSIBLE PUMP-MOTOR ASSEMBLY FOR A DISHWASHER Filed Nov. 28, 1961 v I s lo Illa I06 "5/ A l I I i 5 Sheets-Sheet 2 INVENTOR. Frank E. [.0 Flame His LUZ Aug. 6, 1963 F. E. LA FLAME 3,099,992

REVERSIBLE PUMPMOTOR ASSEMBLY FOR A DISHWASHER Filed Nov. 28, 1961 s Sheets-Sheet 3 INVENTOR. Frank E. La Flame His Attorney States 3,099,992 Patented Aug. 6, 1963 nice 3,099,992 REVERSIBLE PUMP-MOTOR ASSEMBLY FOR A DISHWASIER Frank E. La Flame, Dayton, ()hio, assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Filed Nov. 28, 1961, Ser. No. 155,277 7 Claims. (Cl. 134-182) This invention relates to a domestic appliance and more particularly to an improved reversible pump for circulating water in a dish-washing cycle when operated in one direction and for pumping the waste fluid to drain when operated in another direction.

Current design of appliances in which pumps are utilized includes a system of selectively actuated valves to control the directional flow of fluids pumped during an appliance cycle. The inclusion of such valves adds cost to the manufacturer of the appliance and gives rise to potential servicing problems.

Accordingly, it is an object of this invention to provide a pump with reversible impellers for selectively recirculating fluid or pumping the fluid to drain without auxiliary fluid valves.

A further object of this invention is the provision of a pair of reversible impellers one of which is effective to pump fluid to a spray tube when rotated in one direction while the other serves additionally as a shutoff valve, said other impeller then operating to pump the fluid to drain when operated in another direction.

Another object of this invention is the provision of a pump housing with a first volute for directing a fluid in one direction, a second volute for directing a fluid in a second direction and an impeller in each of said volutes adapted for reversible operation to selectively direct the fluid being pumped.

Another object of this invention is the provision of a simplified pump-motor assembly in which a single memher forms an end plate for the motor and a volute for the pump.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein preferred embodiments of the present invention are clearly shown.

In the drawings:

FIGURE 1 is a schematic side sectional view of a dishwasher suitable for use with this invention;

FIGURE 2 is a side sectional view of one embodiment of the pump-motor assembly of this invention;

FIGURE 3 is a composite sectional view with parts broken away and taken along line 3a-3a for the wash impeller and line 3b3b for the waste impeller; and

FIGURE 4 is a side sectional view of a second embodiment of the pump motor assembly of this invention.

In accordance with this invention and with reference to FIGURE 1, a dishwasher 10 having a top wall 12, a rear panel 14- and a base portion or compartment 16 is adapted to include a dishwashing chamber shown generally at 18. The dishwashing chamber 18 is a generally boxlike receptacle having a depressed bottom defining a sump 20 and a sump outlet 21. The dishwashing chamber 18 has also an access opening 22 in the front wall thereof. Closing the opening 22 is a dishwasher door, shown generally at 24. The door 24 may be hinged to the side panels of the dishwasher 10 in any conventional manner and is adapted to be opened by handle 26. Water for a dishwashing process is supplied through a valve 28 in the lower compartment 16.

Although this invention is not to be limited to a particular type of dishwasher, for purposes of illustration,

the dishwasher 10 is shown provided with a spray tube 30 rotatably supported at 3 2 on a bracket 36 and at 34 on a spray header 42. During a dishwashing cycle, water collecting in sump 20 enters the motor-pump assembly of this invention shown generally at 38, and is recirculated to the spray tube 30 through a conduit 40, the water being so pumped having a swirl imparted to it in the spray tube inlet header member 42. This swirl imparts a rotational movement to the spray tube 30, thereby causing jets of water to issue from the spray tube ports 44 over the surfaces of the dishes that are carried in conventional support racks such as 48. Also, the dishwashing chamber 18 is a heater 50 which is energized at the conclusion of the wash portion of the cycle to raise the temperature within the dishwashing chamber 18 to dry the dishes. It is, of course, possible to energize the heater 50 periodically throughout the dishwashing portion of the cycle to maintain desired higher temperatures within the chamber 18. The dishwashing cycle and thus the pumpmotor assembly is controlled by a timer 58 which programs sequentially the desired dishwashing cycle. For additional details on the dishwashing mechanism outlined broadly hereinabove, reference may be had to the Abresch et al. Patents 2,808,063 and 2,973,907 issued October 1, 1957, and March 7, 1961, respectively.

Where a pump is used in conjunction with a dishwasher, it is necessary firstly to recirculate the water during a dishwashing operation and secondly to pump the water from the dishwasher at the conclusion of the cycle. In the past this has been done with a single direction pump and a diverter valve which is oriented to direct the water either to the spray tube or to drain.- The problem with this prior art arrangement is that the solenoid actuated diverter valve frequently malfunctions and creates service problems for the product. It is therefore the object of this invention to provide a pump-motor assembly which in and of itself will provide the selective direction of the pumped water either to the spray tube or to the drain.

Turning now to FIGURES 2 and 3, the pump-motor assembly 38 is shown comprised of a metallic pump body 60 having an upwardly facing recessed motor compartment or hollow 62 and a downwardly facing wash pump .volute cavity or compartment 64. As an integral part of the casting, a collar 66 extends upwardly and has an axial opening 68 in alignment with the wash pump volute 64. The opening 68 is stepped outwardly to form an enlarged cylindrical portion 70 for receiving a bearing retainer insert 72 and a pair of ball bearings 74 held in the socket or recess 70 by a snap ring 76.

A motor is comprised of a rotor 82 and shaft 84 subassembly and a stator portion 86 fastened as by bolts 88 to upstanding integrally cast bosses 90- in the pump body. An upper annular motor cover 92 is snap fastened as at 94 to the stator as a shield for the motor 80.

With the motor in position the shaft 84 is journalled by the ball bearings 74 and extends through the opening 68 in the pump body into and through the wash pump volute compartment 64 therebelow. In addition to the snap ring 76 on one side of the bearings 74 a snap ring 96 engages the shaft 84 to properly position the motor shaft relative to the pump body. A conventional Water seal arrangement 100* is included at the point the power shaft extends into the pump body to prevent egress of water and ingress of oil or grease during operation of the pump.

A pump cover of phenolic plastic or other suitable material 102 is positioned beneath the pump body 60 and includes a radial flange 104 for fastening the pump cover to the pump body as at 1 06. A pump gasloet 107 may be interposed at this jointure. The upper surface or plate portion 108 of the pump cover completes the wash volute compartment and includes a passageway 110 which interconnects the wash volute compartment with a cylindrical water return compartment 112 defined by the pump cover. The lower end of the water return compartment 112 is open and is closed by an annular disc or baffle plate 114 held in place by a molded waste impeller cover 11 6 of plastic or other suitable material which is fastened as at 118 to the underside of the pump cover. The baflle plate 114 includes a central opening or passageway 120 which interconnects thewater return compartment 112 with a hollowed out waste pump volute 122.

Fluid passageways through (the pump assembly are effected' from a pump inlet 126 in the pump cover 102 which leads into the water return compartment 112. The wash pump volute 64 merges into a wash water supply outlet 128 whereas the waste pump vol-ute 122 merges into a waste water drain outlet 130*. Thus the pump draws fluid from the outlet 21 in the sump by way of a flexible conduit 132 connected to the inlet 126 of the pump cover 102. From this point water is selectively delivered to the spray tube 30 through the outlet 128 in the wash pump or through the waste pump outlet 130 to a drain line 134.

For setting up the selective operation of the pumpmotor assembly 38, the power shaft 84 includes a wash impeller 136 in the wash pump volute 64 and a waste impeller 138 in the waste pump compartment 122. These impellers are molded of a plastic or other suitable material on an insert 140' for the wash impeller and 142 for the waste impeller. A bolt such as 144 is threadedly engaged with the end of the power shaft 84 and acts with a washer 146 to retain the impellers in drivingly connected relationship to the squared-oil power shaft portion 85. With reference. to FIGURE 3, it can be seen that the molded on impeller blades or vanes 148 on the wash impeller and 150 the waste impeller are arranged in opposite fashion so that when the motor 80 is energized for rotation in one direction, the wash impeller is effective to pump and the waste impeller is effective to block how to drain; while energization of the motor in the opposite direction causes the waste impeller 138 to be effective and the wash impeller ineffective. Bo'th impellers are cast or molded with a solid turntable or hub portion such as 154 for the wash impeller 136, 7

In operation, the timer 58 for the dishwasher is effective to energize the motor 80 for operation in one direction to circulate water between the sump and the spray tube 30. At this point, the impeller 136 (operating in a clockwise direction as seen in FIGURE 3) draws fluid from the water return compartment 112 through the impeller inlet 110- and forces the water through the conduit 40 to the spray tube. At this same time, the waste impeller 138 is operating in a clockwise direction (FIGURE 3) which is opposite from its normal pumping direction and such reverse operation serves to valve the inlet opening 120 to prevent water in the return corn pantment 112 from flowing to drain. On the other hand, when the" motor 80 is reversed and the impellers rotate in a counterclockwise direction (FIGURE 3), the water flow will be through the waste pump volu-te compartment 122 with the waste impeller 138 fiorcing (the fluid from the outlet 130 to the drain line 134.

In the foregoing pump-motor assembly, it will be noted that a pair of ball bearings 74 were positioned in side-byside relationship to journal the power shaft 84. In this assembly, the overall height of the pump and motor is reduced. However, a second embodiment shown inFIG- URE 4 presents a less costly arrangement in that only a single ball bearing is involved. This FIGURE 4 arrangement sacrifices a slight amount in overall height to achieve this cost savings. With reference to FIGURE 4, similar parts carry the same reference numeral as set iorthin connection with FIGUREv 2. This pump-motor embodiment 160 ditfers in that a pump body of die cast aluminum 162 is included which has a lower hearing retainer collar 164 and a shouldered peripheral edge 166 to receive a cylindrical sheet metal casing 168 between the pump body 162 and an upper motor housing .170 which is cast with an integral grease retainer portion 172 held to the outer edge by a web: (not shown). The grease retainer has a central collar 174 into which a babbit bearing 176 is press fit. Shimming washers 178 and a spring 180 may be used to provide a thrust to preload the ball bearing 182 therebelow to minimize operating noise. It should be noted that the spring 180 may be omitted since the weight of the power shaft 184 and associated parts also provide a downward bias on the hearing 182 and thereby provide for quiet operation. A lubricant such as permawicking is included in a lubricant compartment 186 formed by the grease retainer and a sheet metal plug 188 is inserted in the open end of the grease retainer to keep dirt from the j'ournalled upper end of the motor shaft 184. The pump housing assembly for the embodiment is the same as set forth hereinabove in connection with the embodiment of FIGURE 2. Namely, a pump cover 104 closes the Wash uolute 64 while a waste impeller cover 116 closes the waste volute 122--an inlet 126 in the pump cover serving to supply both the wash pump and the waste pump for supplying fluid through either the wash pump supply 128 or the waste pump supply 131).

It should now be seen that an improved pump-motor assembly has been provided for selective supply of pumped fluids. A minimum of parts is involved for simplified trouble free operation, and combining a pump with its prime mover eliminates motor components with a consequent saving in material.

While the embodiments of the. present invention as herein disclosed constitute preferred forms, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. In combination, means forming a dishwashing chamber having .a sump outlet, means for admitting wafor to said chamber, means in said chamber for spraying water in a 'dishwashing operation, and pump means having a pump inlet remote from said sump outlet, conduit means for connecting said pump inlet to said sump outlet, a first pump supply outlet connected to said spnay mean-s and a second pump. supply outlet connected to a drain, said pump means including a pump body having an upwardly facing motor recess and a downwardly facing Wash pump volute cavity including said first pump supply outlet, a pump cover fastened to said pump body having a plate portion forming with said wash pump volute cavity a wash water pump compartment and defining a wash water return compartment therebelow including said pump. inlet, 'a waste impeller cover underlying said pump cover and fastened thereto, said waste impeller cover having an upwardly facing waste volute cavity inoluding said second pump supply outlet, a bathe plate means interposed between said covers and forming with said waste volute cavity a waste water pump compartment, means defining supply passage means in said plate portion and said baflie plate means for interconnecting respectively said wash Water return compautment with said wash water pump compartment and said waste water pump compartment, a reversible motor in said motor recess having a verticalpowe'r shaft journaled in said pump body and extending through said wash water pumpcompertinent and terminating in said waste water pump cornpartment, means tor sealing said motor recess from said wash water pump compartment, wash impeller means connected to said power shaft in said wash waterpump compartment and having curved wash pump vanes openative to pump through said first pump supply outlet when said power shaft is rotating in one direction, waste impeller'n'ieahs connected to said shaft in said waste water pump compartment and having curved waste pump vanes operative to pump through said second pump supply outlet when said power shaft is rotating in a reverse direction, and means for energizing said motor selectively to rotate said power shaft in said one direction to pump water from said sump outlet to said spray means and prevent flow of said water to said second pump supply outlet and to rotate said power shaft in said reverse direction to pump said water from said sump outlet to drain.

2. In combination, means forming a chamber having a sump outlet, means for admitting water to said chamber, means in said chamber for spraying water, and pump means having a pump inlet remote from said sump o let, conduit means connecting said pump inlet to said sump outlet, a first pump supply outlet connected to said spray means and a second pump supply outlet connected to a drain, said pump means including a pump body having a motor recess and an oppositely facing spray pump volute cavity including said first pump supply outlet, a pump cover fastened to said pump body having a plate portion forming with said spray pump volute cavity a spray water pump compartment and defining a spray water return compartment including said pump inlet, a Waste impeller cover adjacent said pump cover, said waste impeller cover having a waste volute cavity facing said spray water return compartment and including said second pump supply outlet, a :baffie plate means interposed between said covers and forming with said waste volute cavity a waste water pump compartment, means defining supply passage means in said plate portion and said bafi'le plate means for placing said spray water return compartment in communication with said spray water pump compartment and said waste water pump compartment, a reversible motor in said motor recess having a power shaft journaled in said pump body and extending through said spray water pump compartment and terminating in said waste water pump compartment, spray impeller means connected to said power shaft in said spray water pump compartment and having curved spray pump v anes operative to pump through said first pump supply outlet when said power shaft is rotating in one direction, waste impeller means connected to said shaft in said waste water pump compartment and having curved waste pump vanes operative to pump through said second pump supply outlet when said power shaft is rotating in a reverse direction, and means for energizing said motor selectively to rotate said power shaft in said one direction to pump water from said sump outlet to said spray means and prevent flow of said water to said second pump supply outlet and to rotate said power shaft in said reverse direction to pump said water from said sump outlet to drain.

3. In combination, means forming a chamber having a sump outlet, means for admitting water to said chamber, means in said chamber for spraying water, and pump means having a pump inlet remote from said sump outlet, conduit means connecting said pump inlet to said sump outlet, a first pump supply outlet connected to said spray means and a second pump supply outlet connected to a drain, said pump means including a pump body having a spray pump volute cavity including said first pump supply outlet, a pump cover fastened to said pump body having a plate portion forming with said spray pump volute cavity a spray water pump compartment and defining a spray water return compartment including said pump inlet, a waste impeller cover adjacent said pump cover, said waste impeller cover having a waste volute cavity facing said spray .water return compartment and including said second pump supply outlet, a baflie plate means interposed between said covers and forming with said waste volute cavity a waste water pump compartment, means defining supply passage means in said plate portion and said bafile plate means for placing said spray water return compartment in communication with said spray water pump compartment and said waste water pump compartment, a reversible rotatable power shaft journailed in said pump body and extending through said spray water pump compartment and terminating in said waste water pump compartment, spray impeller means connected to said power shaft in said spray water pump compartment and having curved spray pump vanes operative to pump through said first pump supply outlet when said power shaft is rotated in one direction, and waste impeller means connected to said shaft in said waste water pump compartment and having curved waste pump vanes operative to pump through said second pump supply outlet when said power shaft is rotated in a reverse direction.

4. A pump-motor assembly including a pump inlet, a first pump supply outlet and a second pump supply outlet and comprising a unitary pump body having an upwardly facing motor recess and a downwardly facing first pump volute cavity including said first pump supply outlet, a first pump cover fastened to said pump body having a plate portion forming with said first pump volute cavity a first pump compartment and defining a return compartment therebelow including said pump inlet, a second pump cover underlying said first pump cover, said second pump cover having an upwardly facing second pump volute cavity including said second pump supply outlet, a baflle plate means interposed between said covers and forming with said second pump: volute cavity a second pump compartment, means defining supply passage means in said plate portion and said bafile plate means for interconnecting respectively said return compartment with said first pump compartment and said second pump compartment, a reversible motor in said motor recess having a vertical rotatable power shaft journaled intermediate the ends thereof in said pump body and having one end extending through said first pump compartment and terminating in said second pump compartment, means for sealing said motor recess from said first compartment, first impeller means connected to said power shaft in said first pump compartment and having first curved pump vanes operative to pump through said first pump supply outlet when said power shaft is rotated in one direction, and second impeller means connected to said shaft in said second pump compartment and having second curved pump vanes operative to pump through said second pump supply outlet when said power shaft is rotated in a reverse direction.

5. The pump'motor assembly of claim 4 including a motor housing attached to said pump body in a manner to retain said motor in said motor recess, said motor housing having a sleeve bearing for journaling the other end of said power shaft.

6. The pump-motor assembly of claim 4 wherein said power shaft is journaled solely by a pair of juxtaposed lball hearings in said pump body.

7. In combination, means forming a dishwashing chamber having a sump outlet, means for admitting water to said chamber, means in said chamber for spraying water in a dishwashing operation, and pump means having a pump inlet remote from said sump outlet, conduit means connecting said pump inlet to said sump outlet, said pump means having a pump supply outlet means connected selectively to a drain or said spray means, said pump means including a pump body having an upwardly facing motor recess and a downwardly facing pump volute cavity including said pump supply outlet means, a pump cover fastened to said pump body having a plate portion forming with said pump volute cavity a water pump compartment and defining a water return compart ment therebelow including said pump inlet, a closure un derlying said pump cover and fastened thereto, means defining supply passage means in said plate portion for interconnecting said water return compartment with said water pump compartment, a motor in said motor recess having a vertical power shafit journaled in said pump body and extending into said water pump compartment, means for sealing said motor recess from said water pump compartment, impeller means connected to said power shaft in said water pump compartment and having curved pump operative rto pump through said pump supply oumlet means, and means for energizing said meter selectively to rotate said power shaft to pump Water from said sump outlet 1701 said spray means or $0 rotate said power shaft to pump said water from said sump outlet to drain.

2,492,288 Hollerith Dec. 27, 1949 8. Ruspino Aug. 16, 1955 Abresch Oct. 1, 1957 Terrie Dec. 15, 1959 Israel Feb. 16, 1960 Sasnett Nov. 8, 1960 Sasnett June 6, 1961 Mixon Mar. 6, 1962 FOREIGN PATENTS Germany Jan. 21, 1954 

3. IN COMBINATION, MEANS FORMING A CHAMBER HAVING A SUMP OUTLET, MEANS FOR ADMITTING WATER TO SAID CHAMBER, MEANS IN SAID CHAMBER FOR SPRAYING WATER, AND PUMP MEANS HAVING A PUMP INLET REMOTE FROM SAID SUMP OUTLET, CONDUIT MEANS CONNECTING SAID PUMP INLET TO SAID SUMP OUTLET, A FIRST PUMP SUPPLY OUTLET CONNECTED TO SAID SPRAY MEANS AND A SECOND PUMP SUPPLY OUTLET CONNECTED TO A DRAIN, SAID PUMP MEANS INCLUDING A PUMP BODY HAVING A SPRAY PUMP VOLUTE CAVITY INCLUDING SAID FIRST PUMP SUPPLY OUTLET, A PUMP COVER FASTENED TO SAID PUMP BODY HAVING A PLATE PORTION FORMING WITH SAID SPRAY PUMP VOLUTE CAVITY A SPRAY WATER PUMP COMPARTMENT AND DEFINING A SPRAY WATER RETURN COMPARTMENT INCLUDING SAID PUMP INLET, A WASTE IMPELLER COVER ADJACENT SAID PUMP COVER, SAID WASTE IMPELLER COVER HAVING A WASTE VOLUTE CAVITY FACING SAID SPRAY WATER RETURN COMPARTMENT AND INCLUDING SAID SECOND PUMP SUPPLY OUTLET, A BAFFLE PLATE MEANS INTERPOSED BETWEEN SAID COVERS AND FORMING WITH SAID WASTE VOLUTE CAVITY A WASTE WATER PUMP COMPARTMENT, MEANS DEFINING SUPPLY PASSAGE MEANS IN SAID PLATE PORTION AND SAID BAFFLE PLATE MEANS FOR PLACING SAID SPRAY WATER RETURN COMPARTMENT IN COMMUNICATION WITH SAID 